It has been more than a decade since SPIE Press published the first book on shearography in 2003: Digital Shearography: Theory and Application of Digital Speckle Pattern Shearing Interferometry by Wolfgang Steinchen and Lianxiang Yang. That book has greatly contributed to enabling better understanding and improvement of the digital shearography technique. During the past 13 years, digital shearography has been widely applied by industry and accepted as a practical tool for nondestructive testing; at the same time, the technique itself has been greatly improved. This new book presents the principles and applications of phase shift digital shearography, especially spatial phase shift digital shearography, and reviews the state-of-the-art improvements and new developments of digital shearography for nondestructive testing and strain measurement. The authors provide a unified, self-contained treatment of the theory, practice, and applications of shearographic interferometry with problems and questions. The book will meet the requirements of graduate students, as well as be of assistance in research and industry applications.

Preface

It has been more than a decade since SPIE Press published the first book on shearography in 2003: Digital Shearography: Theory and Application of
Digital Speckle Pattern Shearing Interferometry, by Wolfgang Steinchen and
Lianxiang Yang. That book has greatly contributed to enabling better
understanding and improvement of the digital shearography technique. During
the past decade, on one hand, digital shearography has been widely applied by
industry and accepted as a practical tool for nondestructive testing; on the other
hand, the technique itself has been greatly improved. Consequently, it is time to
provide the reader with the recent developments and applications of digital
shearography. This new book aims to present the principles and applications of phase shift digital shearography, especially spatial phase shift digital shearography, and review the
state-of-the-art improvements and new developments of digital shearography for
nondestructive testing and strain measurement.

During the last decade, the rapid development of micro-electronic technology
and computer science has generated many new possibilities for digital
shearography and has enabled the development of spatial phase shift
shearography, which is a great improvement over earlier digital shearography
techniques. Spatial phase shift shearography has great potential for high-speed
measurements; it fills the gap in the measurement capability of shearography for
quantitative dynamic measurement. In writing this book, we have attempted to
provide a unified, self-contained treatment of the theory, practice (with problems
and questions), and applications of shearographic interferometry. We present the
subject in such a manner that the book will meet the requirements of graduate
students as well as be of assistance to the experienced researcher.

Some contents of the book draw from research carried out with Dr.
Yonghong Wang, Dr. Sijing Wu, Dr. Nan Xu, Mr. Xu Chen, Mr. Jianfei Sun, Mr.
Xingya Gao, and Dr. Sheng Liu. All are (or were) research assistants in the
Optical Laboratory of Oakland University and are gratefully acknowledged. We
appreciate the help of Mr. Junrui Li, Mr. Tian Bai, Mr. Boyang Zhang, and Ms.
Haley Linkous in the careful correction of the manuscript as well as the English.
Special thanks go also to Mr. Bernard Sia of US TACOM in Warren, Michigan,
who carefully and thoroughly read the manuscript and provided valuable
criticism. We want to express our sincere thanks to Ms. Dara Burrows, a Senior
Editor of the SPIE Press, who contributed immeasurably to this book through her
excellent publishing experience and her generous personal cooperation and
assistance. We also gratefully acknowledge the help, comments, and suggestions
offered by Dr. Y. Y. Hung, a pioneer in shearographic research.

To Dr. Yang's wife, Yang HU, to his son and daughter, Yang and Jessica,
and to Xin Xie's wife, Xiaona LI, we offer love along with our appreciation of their
support and patience.